1. Field of the Invention
This invention relates to apparatus and process for making cants from log sectors. Each log sector for making a cant will have an apex angle between about 20 degrees and 180 degrees, usually within the range of 30 degrees to 120 degrees, and such cant will be defined by two radial planes and the round or arcuate portion of the log circumference bridging between the outer edges of such planes.
The log sector will be supported between and by two centers engaging opposite ends of the log sector, respectively, to enable the log sector to be turned for presentation to an overhead sawing apparatus including a head saw and an edger saw in juxtaposed orthogonal relationship mounted on a carriage which is reciprocable along the length of the log sector on a track adjustable transversely and elevationally and somewhat angularly.
2. Prior Art
Logs have been sawn by prior apparatus while being held between centers or dogs so that the log could be turned about the axis of such centers. One such apparatus is shown in U.S. Pat. No. 4,271,736, issued Jun. 9, 1981for Sawmill Apparatus with Vertically Movable Logging Dogs. Log-supporting dogs are mounted on a carriage relative to which the dogs are adjustable elevationally independent of each other but simultaneously, and the dogs can be rotated conjointly through 90 degrees for simultaneously rotating a log engaged thereby, whereby a second saw cut can be made in perpendicular relation to a first saw cut (column 3, lines 14 to 18 and column 4, line 64 to column 5, line 4).
The carriage on which the log-supporting dogs are mounted is reciprocated to carry the log through a band saw apparatus comprising a pair of endless bandsaw blades (column 6, lines 11 to 31). The spacing between the bandsaw blades can be varied depending upon the size of the log and the direction in which the log is passed through the bandsaws.
Log-sawing apparatus in which a log to be sawn is supported between and by clamps engaging the opposite ends of a log is disclosed in U.S. Pat. No. 4,867,213, issued Sep. 19, 1989, for System for Orienting Logs for Lumber Processing. This apparatus includes C-shaped clamps which fit around and receive the log from spindles that support the log while the apparatus is being set up. The clamps are driven into the log ends and the spindles are retracted (column 4, lines 36 to 39). Such clamps are mounted on a carriage which is reciprocated along tracks past a saw represented by the line 40 in FIG. 8 (column 4, lines 42 to 56). The knees supporting the clamps C can be moved transversely of the saw line such as in two-inch increments to cut successive boards or planks from the log (column 4, lines 51 to 56). When one side of the log is sawn down to the center cant, the log is pivoted 180 degrees and the sawing operation is repeated for the other side of the log (column 4, lines 56 to 58). Alternatively, the clamps can be turned for sawing the log on all four sides (column 4, line 65 to column 5, line 1).